God of War I:
Kratos, the main character, is a Spartan warrior who has led thousands of men into battle and victory over the course of his life, and has a wife and daughter. His wife and daughter wanted him to cease from his bloodlust as it was taking over him, but he didn't submit. One day, the Barbarians from the East challenged Kratos and his army and wiped out all of his men and nearly killed Kratos.
When Kratos was facing his demise, he prayed to the God of War, Ares, to save his life and destroy his enemies. If he did so, he would surrender the rest of his life to the service of the God of War. Ares came down, wiped out the Barbarians and their king, and so Kratos was now a slave of Olympus and to Ares.
Kratos pillaged, destroyed and murdered villages and cities in the name and glory of Ares. He also is the reason Atlas carries the earth on his shoulders, because Kratos imprisoned him there under the service of Olympus.
You learn that, Ares tricks Kratos into killing his wife and child by planting them inside a home he was told to invade. Ares believed that, with Kratos' emotional investments gone, there was no longer anything holding him back from full service and slavery to the God of War. The oracle that warned him not to invade the home, now punishes Kratos by forcing him to wear the ashes of his dead family on his skin, turning it white, and giving him the name "Ghost of Sparta". The memories of this event haunt Kratos for the rest of his life.
Anyway, one day, Athena, the Goddess of Wisdom tells Kratos that Olympus is growing aggravated with Ares' meaningless slaughter. He's become too powerhungry, and since the gods are forbidden from directly warring against each other, Athena asks Kratos to find Pandora's Box. That box will give a mortal the ability to kill a god, so Athena wants Kratos to use it to kill Ares, because he is senselessly attacking Athena's guardian city, Athens, Greece. She promises that Kratos' sins against the people of Greece and his family will be forgiven if he takes this quest.
Kratos goes on an epic journey to the Desert of Lost Souls to find Pandora's Box inside Pandora's Temple. He finds it, but is killed by Ares when he senses its liberation from its temple. Kratos goes to the Underworld, escapes by the mercy of Zeus, and intervenes as he uses Pandora's Box to become the size of a god.
Kratos kills Ares. Olympus forgives Kratos for his sins, but Kratos becomes infuriated when he learns that he misunderstood the gods, as well as the gods just being tricky bastards, that his memories wouldn't be erased. They would continue to haunt him for the rest of his life, regardless of his past being forgiven. No one could forget what he had done.
Kratos wanted to kill himself, but Athena intervened and said she couldn't allow it to happen. The God of War was dead, and Olympus had an empty throne. Kratos took up the title of the new God of War.
God of War II:
Kratos, the new God of War, has found a new home in the alliance with Sparta. They worship him as their god and he enjoys helping them defeat their foes as a mighty god. Life's pretty good it seems, except he is teeming with fury for the gods and how they deceived him into doing their Pandora quest in the last game without wiping out his painful memories. Kratos' only joy is destroying cities in the name of Sparta.
Athena tells Kratos that the gods are growing angry with Kratos' wreckless destruction, similar to why they grew angry with Ares.
When Sparta asks Kratos for help in Rhodes, Kratos ignores Athena and attends to the matter himself.
As he's trying to destroy Rhodes, Zeus comes in the form of an eagle and takes away a lot of Kratos' godly powers, and endows it upon the Colossus of Rhodes. The Colossus now comes alive and is trying to kill Kratos and the Spartans.
Kratos, still wielding some godly power, tracks down the colossus, when suddenly Zeus intervenes again. He offers Kratos the Blade of Olympus, the weapon that ended the Great War against the Titans. He tells Kratos to drain his godly powers into the sword so he can defeat the Colossus.
Kratos does as commanded, believing in Zeus' strange sincerity, and defeats the Colossus of Rhodes. Before its downfall, its hand crushes Kratos, and he realizes that he is now mortal. He has to retrieve the Blade of Olympus if he wants his powers back.
As he makes his way over, Zeus comes down and confronts Kratos. It's now apparent that it was a trick to get Kratos to discard his godly powers, and so that Zeus could kill him. Zeus kills Kratos with the Blade of Olympus, because Kratos has grown dangerous for the gods with his insolence and anger.
In the Underworld again, the Titan Gaia (the narrator throughout the series, as it is revealed) saves Kratos and says that he wasn't meant to die here. She and the other Titans hate Zeus for punishing and exiling them after the Great War. She tells Kratos to find the Sisters of Fate, the beings that control every living being's destiny and time, and find a way to return to the moment before Zeus killed him, so that he could kill Zeus instead.
Soooo...Kratos embarks on another epic quest to the Sisters of Fate to turn back time and get a second chance at his destiny.
He reaches the Island of the Fates, and Gaia explains why they hate Zeus. Basically, he was Kronos' son, and Kronos tried to eat all his sons in fear that they would rise up and conquer him. Zeus survived, though, escaping his consumption, and Gaia took care of him until he grew up and became a strong, young god. Zeus' anger against his father, Kronos', and the Titans, caused him to war against them and eventually defeat and punish them all. He attacked all the Titans, including Gaia, the one that raised him, for the sins of just one, Kronos.
So, now you know why Gaia likes you so much.
So after a long road, meeting various other people that want to reach the Fates to change their destinies, like the Barbarian king you killed in the first game, Icarus, Theseus, Perseus, etc., you find the Sisters of Fate. You also find a Spartan captain you met at the beginning of the game, who reveals to you that Zeus wiped out all of Sparta after he killed Kratos.
They tell you that they are the ones that allowed you to come this far. No matter, Kratos has an epic boss fight where he kills the Fates and traps them in a limbo between time and space.
There is a third sister, however, who is this big fatass worm who spins the threads of fate that control everyone's destiny. You eventually kill her, and take over her loom and mirrors to return to the point Zeus betrayed you.
Zeus is astonished that the Fates allowed you to proceed, but you just tell him that you killed them.
Kratos attacks Zeus with the Blade of Olympus, and nearly kills him. Just before the final blow, Athena jumps in front and Kratos accidentally kills her. In her dying breath, she tells him how if he kills Zeus, all of Olympus will die as well. Every god will deny Kratos. And she pleads to him not to kill Zeus, because Kratos is Zeus' son, and just like Zeus did many years ago, Kratos is continuing the cycle of vengeance against fathers. She dies, Kratos is pissed, and Zeus escapes to Mt. Olympus.
Kratos returns to the mirror and looms, and finds the past where Gaia and the Titans were about to be defeated in the Great War. He asks Gaia and the others to join him in the present where Zeus has retreated to Mt. Olympus.
With this, Kratos, and the Titans, climb Mt. Olympus and seek to kill Zeus and the other gods once and for all, in the name of vengeance.
God of War III:
???
